Fill (fill)
The Fill property specifies how an image is resized or clipped to fit an area.
This property is relevant when both X-Size and Y-Size are set so that the outer image bounds are defined.
Note: The Fill property replaces the previous tile
            property. When a document containing the tile property is opened
            in version 2.4x or higher, it is automatically replaced with this property.
        Type: Enum.
Valid values:
- completely - The image expands or shrinks to fill the specified area. The aspect ratio is not respected.
 - preserveAspectRatio - The image expands or shrinks to fit the specified area. The
                aspect ratio is respected.Note: To shrink the final bounds of the box so that it has the same size as the image, set the X-Size Adjustment and Y-Size Adjustment properties to shrinktoChildren.
 - tile - The image is painted as tiles into the specified area.
 - clip - The image is painted without scaling, and clipped at the edges if it is too large to fit into the specified area.
 
Default value: completely
You can find the Fill property in the Image category of the Properties view.